Process of making steel.



W mw H 0 CHUTE PRGESS 0F MAKING STEEL.

APPLICATION FILED JAN.14,1907.

Witnesses 4U y oflfuel as -compared with the ordinary smelt- UNITEDSTATES HARRY O. CHUTE, OF CLEVELAND, OHIO.

Pnocnss 0F MAKING STEEL.

Specification of Letters Patent.

Patented Dec. e4, 1907.

Application filed January 14. 197. Serial No. 352,269.

To all whom it may concern.

Be it known that I, HARRY O. CHUTE, a

4citizen of the United States, residing in Cleve* land, in the county ofCuyahoga and State of Ohio, have invented certain new and usefulImprovements in Processes of Making Steel; and I do hereby declare thefollowing to be a full, clear, and exact description of thc saine, suchas will enable others skilled in the art to which it appei'tains to makeand usc the same. Y y

This invention relates to processes of making steel and consists 4in amethod ofsinclting low-grade and impure ores to. produce a special ironand in systematically reiining such iron; all as more fully hereinafterset forth and as claimed.

-Many non-besseiner oresl are highly sili- 4 cious and do not make goodbasic pig iron,

and these ores are frequently high in sulfur, or, in some cases, theonly fuels available for smeltingthem are high in sulfur. VV ith suchores and such fuels, 'in ordinary practice if the furnace is run hot asilicious pig iron isv saturated with carbon. The pro produced Whichcannot be easily handled in a basic furnace. If the furnace is run cold,a sulfurousl pig iron is produced which cannot be easily freed ofimpurities in the basic open hearth. This is especially true in theabsence of manganese in the ores,- a very frequent condition.

It is the purpose of the present invention to treat these. ores by a'simle, cheap and ready method, making ava' able large deposits noWconsidered-unavailable certain of these ores best adapted to the resent.proc ess being generally considered t for nothing because too impure ortoo-deficient in Inanganese. y' y I have discovered that by using anexcess ing operation to produce basic pig ironin the blast furnace andthereby running such furnace very hot, I can charge it With'an ore'mixture. containing man anese and phosphorus, both preferably ad ed asby-products resulting from a later operation, and with enough ime tofnake a basic slag, and thereby almost completely eliminate sulfur inthe slag as manganese sulid, producing a veryl hot and iiuid pig iron,rich'in silicon and phosphorus, all the phosphorus in the charge,

substantially, appearing in the iron.

half the manganese in the charge also appears in the iron and suchl ironis ractical y dliict of this About' operation is a hi hly silicious,very hot pig iron, Which may eV termed superheated as compared with theordinary temperature at which iron is tapped from furnaces producingbasic pig iron, While the sulfur is mostl -eliminated in the basic slagas sulfid of ca cium or manganese. While other pio iron containing muchsilicon and phosphorus, produced in other methods of operating thefurnace, may be employed for my purposes, as hereinafter setforth, suchother pig iron must be heated to a temperature analo ous to that of thepig iron produced in the a ove. operation; inust be superheated ascompared with the ordinary 'tapping temperature of basic pig. Asuperheated iron of this character, I have discovered, can be readilydesiliconized 'by causing it to fioW into contact `with oxid of iron.The oXid may be dusted on the hot, very fluid iron by any suitablemechanism or the container may have the bottom lined with iron ore ormill scale. c In pig iron of the described character made in thedescribed vmanner there is enou h sensible heat to inaugurate thereaction Whi e' its comosition insures that the reaction With the ironoxid shall be sufficiently exothermic to maintain itself. `The iron doesnot become chilled and is preserved in the melted condi- I tion Whilethe larger part of the silicon is removed and the carbon begins to beattacked. The presence of the phosphorus is useful in maintaining thefluidity during the reaction. It remains in the iron While the siliconisbeing removed. The manganese in the iron is jlargely attackedand removedduring the oxidation of the silicon, going into the slag use in thefurnace. In this operation ad vantage is taken of the fact that with ahigh temperature and a silicious iron, the silicon and manganese arereferentially attacked.

It is important t at the uantity of iron ore orother iron oxid -broug tinto contact With the ironshould be limited to that necessary to-removethe silicon, withoutotherwise changing materially thel composition 'orfluidity of the pig iron. This may be readily effected by control of theamount dusted in orlengtheningor shortening the time of contact of the.molten metal With ironoxid.

The product of the reaction on the molten metal, or slag, may be skimmedoff by any suitable means. Asstated, it is to be reserved ior re-use inthe blast furnace. One appropriate Way of separating it is by the nantmass of molten metal, in which the ref tions.

' slag from the desiliconizing, which is silicate shown more or lessdiagrammatically, one

`manganese, forming-a floating slag of siliideal material for treatmentin a basic open 'manganese be absent in the ore, some must employed inthe auxiliary i In this showing, 1 is the usual type of blast use of anauxiliary furnace connected With the container in which the Ytreatmentwith oxid is performed and serving at once as slag-separating means,re-heating means and means for forming a reservoir or domiaction can beequalized, continued orregulated, to be drawn on for the later opera-The purified, skimmed iron is still essentially pig iron but is nowlargelyfreed from silicon, sulfur and manganese but contains largeamounts of carbon and phosphorus, rendering it fusible, fluid and anhearth furnace in which it may be treated in the usual way to eliminatethe carbon and phosphorus, with formation of the well known phosphoricbasic slag. lThis phosl phoric slag, being highly4 basic and containinga considerable amount of iron as well as thephosphorus, is Well suitedas, an mgredient of the charge in the blast furnace to ,f

produce the high-phosphorus pig iron. It may he used for this purpose,wholly or in part. Or it may be utilized: for other purposes. 'Therewill always be an excess oi' phosphoric slags. A considerable economy 1nthe process is effected by returningr the of iron and man anese, to thefurnace together with the s ag from the basic hearth, whereby the ironmay be recovered andthe manganese and phosphorus re-utilized. If

be supplied from any convenient. source. Running the furnace hot withsuflicient fuel to produce the describedpig iron, a rich gas containingphosphoric and 1s obtained which may he advantageously furnace an( inthe basic open hearth furnace.`

In the accompanying illust-ramon, I have assemblage of apparatus of themany combine-tions adapted to perform my process.

furnace, shown fragment arily, provided with cinder notch 2 and ironnotch 3, The latter' leads into trough 4, provided With the usualskimming .a para-tus 5 and slag outlet. 6. The trough 1s lined, asusual, Wlth irebrlck or other refractory material, and as shown, it isalso lined in use for a portion of its length With iron oxid or millscale 7. As an alternative means of using the iron oxid, feeder spout 8from the hopper 9 may be employed.

It may also be used in conjunction with the stated lining. The amount ofiron oXi used in either or both Waysis of course adjustedl to the tenorin silicon of'l the pig iron.` A portion of the trough may be covered,as shown at 10., During transit' throu h the trough in contact with theiron oXid, t e iron ls deprived of its silicon and partly of its Cates.vThis is skimmed ott by an ordinary i skimmer 11 and passes out throu hthe side trough 12, Where it cools and is roken u for return to theblast furnace. The desilicorized iron, still fluid because of its carbonan skimmer and into and through a movable trough 13l into the auxiliaryfurnace and reservoir 14'. From able trough 16 into the basic openhearth. furnace 1,7. This latter should be of the usual or standardbasic open hearth construction, With the usual regenerative chambers 18,the gaseous fuel being admitted through the valve 20 and conduit22 tothe regenerative chambers and thence to the furnace in the usual manner.The air similarly reaches the furnace through valve 19. The hot rich gasproduced by the blast furnace While Working in this process is Welladapted to heat the basic open hearth furnace.

1. The process-of making steel which consists in smelting iron from abasic charge containing phosphorus and manganese under properthermalconditions to roduce a superheated pig iron rich in si icon andphosphorus and a sulfurous slag, contacting the superheated pig ironwith suiicient oxid of iron to remove silicon and then treating thedesiliconized iron to remove phosphorus and carbon.

making steel rwhich coniron from a basic charge m-anganic slag from alater operation under pro er thermal conditions to produce a super eatedig iron rich `in silicon'and phosphorus andD a sulfurous slag,contacting the superheated pig iron with sufficientoxid of iron toremove silicon and removing and reserving the produced slag forsubsequent use in the smelting, and then treating the desiliconized ironto remove phosphorus and carbon and -2. The process of sists'in smeltingl produce a basic slag.

3. The process of making steel Which consists in smelting siliciousnon-bessemer ores under proper thermal and fluxing conditions to producea su erheated pig iron rich in silicon and phosp orus and asulfurousslag,

contacting the superheated lpig iron With phosphorus content, passesunder the this it is tapped from l time to time through the spout 15 andmov-l suflicient oxid of iron to remove silicon, and

' 5. The process of making steel which consists in smelting siliciousnon-bessemer ores in the presence of basic slag containing phosphorusand a silicate slag containing manganese under proper thermal conditionsto produce a superheated pig iron'rich in silicon and phosphorus and asulfurous slag, producing a flowing current of such molten superheatedpig iron and contacting it in transit with sufiicient oXid of iron tovremove `,silicon and form a silicate slag containing manganese, and thentreating the desiliconizfed iron to remove phosphorus and carbon andform a basic slag containing hosphorus.

6. rlh'e process of making steeFWhich consists in smelting siliciousnon-bessemer ores under proper thermal and fluxing conditions to formasuperheated pig iron rich in silicon and phosphorus and a sulurous slag,roducing a iioWing current of such mo ten superheated pig iron andcontacting it 'in transit with sufficient oXid-of iron to remove siliconand then treating the desiliconized iron by the basic open'hearthprocess to remove phosphorus and carbon. Y

7. The process of making steel Which lconsists in producing molten pigiron containin silicon and phosphorus and in a superheate st ate,contacting it While in said superheated state with sufficient oxid ofiron to remove silicon and form a silicate slag, and then treating thedesiliconized iron by the basic open hearth process to remove phosphorusand carbon.

8.' The process of makmg steel Which conslsts in smeltmg s1l1c1ousnonebessemer ores under proper thermal and luXing conditionsl HARRY o'.oHU'rE. Witnesses B. L. CHADWLL, K. P. McELRoY.

